jazzyvee mentioned that Alembic uses inserts for everything EXCEPT the strap button. A threaded insert here would definitely hold better, but makes changing strap buttons really difficult as the various brands used different sized hardware, and it's unusual hardware as well. It would probably be easier to get a hex head capscrew that fit inside a Dunlop Straplok than to find another phillips head wood screw with the tiny head, but serendipity would assure that you could never find the necessary hex key then!
I agree that would be nice though. I have some old Warwicks (around 1990) that have inserts for the Schaller straplocks and they work great (metal-to-metal attachment and you could Loctite them too) but I'm sure that caused a lot of consternation for people who didn't like those Schaller pins.